1. Field of the Invention
The present invention is generally in the field of electrical circuits and systems. More particularly, the invention relates to lighting systems utilizing electrical circuits.
2. Background Art
Arrays of connected loads, for example, lighting arrays, or more particularly light emitting diode (LED) arrays, are known and used in a variety of electronic applications, such as in LED displays, color mixing, display backlighting, for example, liquid crystal display (LCD) backlighting, and in general lighting fixtures. The array of connected loads can include a large number of loads, for example, LED displays, such as electronic billboards, can have upwards of one million LEDs. It is generally desirable to connect the large number of LEDs in series resulting in a relatively high-voltage, low-current arrangement. Disadvantageously, when LEDs are connected in series, the failure of one of the LEDs can cause an open circuit, thereby causing a failure of the entire array of series-connected LEDs.
Thus, LED arrays often include a series-parallel arrangement where stings of series-connected LEDs are connected in parallel. However, large arrays of series-parallel connected LEDs often require a large number of parallel connections, particularly in LED displays. Even then the failure of one of the LEDs in a particular string of series-connected LEDs can cause a failure of the entire string of LEDs, which can be especially noticeable when there are a large number of LEDs in the string, for example, in LED displays. Furthermore, having a large number of parallel connections in the series-parallel arrangement can result in high current requirements and increased complexity.
Thus, there is a need in the art for the capability to provide series-connected LED arrays having a large number of LEDs while overcoming the drawbacks and deficiencies in the art.